Aspectos epidemiológicos y moleculares implicados en la sensibilidad disminuida a la vancomicina en Staphylococcus aureus

Staphylococcus aureus is an opportunistic pathogen that causes disease in humans and animals. Since 1997 there have been worldwide reports of S. aureus with reduced susceptibility to vancomycin (VISA), and strains with heterogeneous resistance (hVISA). The mechanism responsible for this resistance i...

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Autor principal: Di Gregorio, Sabrina Noelia
Otros Autores: Famiglietti, Angela
Formato: Tesis doctoral acceptedVersion
Lenguaje:Español
Publicado: Facultad de Farmacia y Bioquímica 2015
Materias:
S Aurus
Varcomicina
Heterorresistencia
Ciencia de la vida
Acceso en línea:http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=posgraafa&cl=CL1&d=HWA_1130
http://repositoriouba.sisbi.uba.ar/gsdl/collect/posgraafa/index/assoc/HWA_1130.dir/1130.PDF
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Repositorio Digital de la Universidad de Buenos Aires (UBA) de Universidad de Buenos Aires
id I28-R145-HWA_1130
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spelling I28-R145-HWA_11302019-09-25 Staphylococcus aureus is an opportunistic pathogen that causes disease in humans and animals. Since 1997 there have been worldwide reports of S. aureus with reduced susceptibility to vancomycin (VISA), and strains with heterogeneous resistance (hVISA). The mechanism responsible for this resistance is not fully understood. In addittion, detection of hVISA phenotype is difficult in clinical settings.\nThis work describes for the first time the prevalence and molecular characterization of isolates hVISA in a hospital from Argentina. Different methodologies for the detection were evaluated. Additionally, the molecular mechanism probably involved in the reduced susceptibility to vancomycin was studied.\nNo VISA isolate was recovered and hVISA phenotype occurred in 3.3% of S. aureus bacteremia studied. An association between hVISA phenotype and multiple episodes of bacteremia was found, and a combination of methods was proposed to warn of a possible hVISA in those laboratories that can not regularly perform confirmatory methodology.\nThe change in peptidoglycan metabolism of hVISA/VISA strains found in this thesis may be due to diverse genetic changes. Increased IS256 transposition was also associated with this phenotype. Fil: Di Gregorio, Sabrina Noelia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Famiglietti, Angela Facultad de Farmacia y Bioquímica Mollerach, Marta Di Gregorio, Sabrina Noelia 2015-03-10 Staphylococcus aureus es un patógeno oportunista que causa enfermedad en el hombre y en los animales. Desde 1997 se han reportado a nivel mundial cepas de S. aureus con sensibilidad disminuida a vancomicina (VISA), y cepas con resistencia heterogénea (hVISA). El mecanismo responsable de dicha resistencia aún no ha sido completamente elucidado. Sumado a esto, la detección del fenotipo hVISA es dificultosa en laboratorios clínicos.\nEste trabajo describe por primera vez la prevalencia y la caracterización molecular de aislamientos hVISA en un hospital de Argentina y evalúa distintas metodologías para su detección. Adicionalmente, se estudian las bases moleculares posiblemente implicadas en la susceptibilidad disminuida a vancomicina.\nNo se encontraron aislamientos VISA y el fenotipo hVISA ocurrió en el 3,3% de las bacteriemias por S. aureus estudiadas. Se encontró una asociación entre el fenotipo hVISA y episodios múltiples de bacteriemias, y se propuso la combinación de métodos para alertar de un posible hVISA en aquellos laboratorios en donde no se puede realizar la metodología confirmatoria de rutina.\nLa modificación en el metabolismo del peptidoglicano en cepas hVISA/VISA hallada en esta tesis podría deberse a diversos cambios genéticos. Asimismo se encontró un aumento de la transposición de IS256 asociado a dicho fenotipo. application/pdf Cavallaro, Lucía Sordelli, Daniel Lopez Camelo, Jorge S Aurus Varcomicina Heterorresistencia spa Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by-nc-nd/2.5/ar/ Ciencia de la vida Aspectos epidemiológicos y moleculares implicados en la sensibilidad disminuida a la vancomicina en Staphylococcus aureus info:eu-repo/semantics/doctoralThesis info:ar-repo/semantics/tesis doctoral info:eu-repo/semantics/acceptedVersion http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=posgraafa&cl=CL1&d=HWA_1130 http://repositoriouba.sisbi.uba.ar/gsdl/collect/posgraafa/index/assoc/HWA_1130.dir/1130.PDF
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-145
collection Repositorio Digital de la Universidad de Buenos Aires (UBA)
language Español
orig_language_str_mv spa
topic S Aurus
Varcomicina
Heterorresistencia
Ciencia de la vida
spellingShingle S Aurus
Varcomicina
Heterorresistencia
Ciencia de la vida
Di Gregorio, Sabrina Noelia
Aspectos epidemiológicos y moleculares implicados en la sensibilidad disminuida a la vancomicina en Staphylococcus aureus
topic_facet S Aurus
Varcomicina
Heterorresistencia
Ciencia de la vida
description Staphylococcus aureus is an opportunistic pathogen that causes disease in humans and animals. Since 1997 there have been worldwide reports of S. aureus with reduced susceptibility to vancomycin (VISA), and strains with heterogeneous resistance (hVISA). The mechanism responsible for this resistance is not fully understood. In addittion, detection of hVISA phenotype is difficult in clinical settings.\nThis work describes for the first time the prevalence and molecular characterization of isolates hVISA in a hospital from Argentina. Different methodologies for the detection were evaluated. Additionally, the molecular mechanism probably involved in the reduced susceptibility to vancomycin was studied.\nNo VISA isolate was recovered and hVISA phenotype occurred in 3.3% of S. aureus bacteremia studied. An association between hVISA phenotype and multiple episodes of bacteremia was found, and a combination of methods was proposed to warn of a possible hVISA in those laboratories that can not regularly perform confirmatory methodology.\nThe change in peptidoglycan metabolism of hVISA/VISA strains found in this thesis may be due to diverse genetic changes. Increased IS256 transposition was also associated with this phenotype.
author2 Famiglietti, Angela
author_facet Famiglietti, Angela
Di Gregorio, Sabrina Noelia
format Tesis doctoral
Tesis doctoral
acceptedVersion
author Di Gregorio, Sabrina Noelia
author_sort Di Gregorio, Sabrina Noelia
title Aspectos epidemiológicos y moleculares implicados en la sensibilidad disminuida a la vancomicina en Staphylococcus aureus
title_short Aspectos epidemiológicos y moleculares implicados en la sensibilidad disminuida a la vancomicina en Staphylococcus aureus
title_full Aspectos epidemiológicos y moleculares implicados en la sensibilidad disminuida a la vancomicina en Staphylococcus aureus
title_fullStr Aspectos epidemiológicos y moleculares implicados en la sensibilidad disminuida a la vancomicina en Staphylococcus aureus
title_full_unstemmed Aspectos epidemiológicos y moleculares implicados en la sensibilidad disminuida a la vancomicina en Staphylococcus aureus
title_sort aspectos epidemiológicos y moleculares implicados en la sensibilidad disminuida a la vancomicina en staphylococcus aureus
publisher Facultad de Farmacia y Bioquímica
publishDate 2015
url http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=posgraafa&cl=CL1&d=HWA_1130
http://repositoriouba.sisbi.uba.ar/gsdl/collect/posgraafa/index/assoc/HWA_1130.dir/1130.PDF
work_keys_str_mv AT digregoriosabrinanoelia aspectosepidemiologicosymolecularesimplicadosenlasensibilidaddisminuidaalavancomicinaenstaphylococcusaureus
_version_ 1766017452614877184

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